The antiviral drug Tamiflu could halve the potential death toll from an influenza pandemic if it was used both to treat and prevent the disease, its maker Roche said on Friday.

Research presented by Beate Sander of the University of Toronto, Canada, showed a stockpile of Tamiflu sufficient to cover 65 percent of a country’s population could cut deaths by approximately half, Roche said.

Tamiflu is seen as one of the best defenses against a possible bird flu pandemic. It is recommended by the World Health Organization as a first-line defense, and governments and are stockpiling the drug.

Some governments are now planning stockpiles sufficient to will allow them to provide Tamiflu preventatively to people who have been in close contact with infected individuals, Roche said.

“The reality is that country stockpiles of Tamiflu are limited and are targeted at treatment only rather than treatment and prevention,” the Roche statement said.

“However, some governments are now planning for sufficient antiviral stockpiles that will allow them to provide Tamiflu preventatively to close contacts of infected individuals, it said.”

Details were presented at an influenza conference in Toronto.